import java.util.Scanner;
public class ChooseTest {
    public static void main(String[] args) {
        Scanner in=new Scanner(System.in);
        Choose a=new Choose();
        System.out.println("请输入数字选择：");
        try{
            a.setA(in.nextInt());
//            a.setA(in.nextInt());
            while(a.getA()>=0&&a.getA()<=4)
            {
                a.setA(in.nextInt());
//                throw new Exception("请重新输入：");
            }

        }catch (Exception b){
            b.printStackTrace();
        }
    }
}
